
Originally Posted by
basucat
To check if the hydrovac is working, step on the brake while engine is off. Start the engine, the brake pedal should sink a bit since vacuum will energize the hydrovac. If the pedal does not sink, there is possibly problem sa hydrovac - check for broken vacuum hoses. If the pedal sinks, have the brake master cylinder checked.
I assume that original pa yung hydrovac and yung master cylinder has not yet been replaced. Sometimes kasi mayroon mismatch itong dalawa kung pinalitan.